diff --git a/src/Illuminate/Container/Container.php b/src/Illuminate/Container/Container.php
index 63607ee37284..39bf3bb59726 100755
--- a/src/Illuminate/Container/Container.php
+++ b/src/Illuminate/Container/Container.php
@@ -7,6 +7,7 @@
 use LogicException;
 use ReflectionClass;
 use ReflectionParameter;
+use Illuminate\Support\Arr;
 use Illuminate\Contracts\Container\BindingResolutionException;
 use Illuminate\Contracts\Container\Container as ContainerContract;
 
@@ -134,22 +135,18 @@ class Container implements ArrayAccess, ContainerContract
     /**
      * Define a contextual binding.
      *
-     * @param  string|array  $concrete
+     * @param  array|string  $concrete
      * @return \Illuminate\Contracts\Container\ContextualBindingBuilder
      */
     public function when($concrete)
     {
-        if (is_array($concrete)) {
-            $alias = [];
+        $aliases = [];
 
-            foreach ($concrete as $c) {
-                $alias[] = $this->getAlias($c);
-            }
-        } else {
-            $alias = $this->getAlias($concrete);
+        foreach (Arr::wrap($concrete) as $c) {
+            $aliases[] = $this->getAlias($c);
         }
 
-        return new ContextualBindingBuilder($this, $alias);
+        return new ContextualBindingBuilder($this, $aliases);
     }
 
     /**
diff --git a/src/Illuminate/Container/ContextualBindingBuilder.php b/src/Illuminate/Container/ContextualBindingBuilder.php
index bf15920f74f1..2bd4b5ad9d8f 100644
--- a/src/Illuminate/Container/ContextualBindingBuilder.php
+++ b/src/Illuminate/Container/ContextualBindingBuilder.php
@@ -2,6 +2,7 @@
 
 namespace Illuminate\Container;
 
+use Illuminate\Support\Arr;
 use Illuminate\Contracts\Container\ContextualBindingBuilder as ContextualBindingBuilderContract;
 
 class ContextualBindingBuilder implements ContextualBindingBuilderContract
@@ -61,14 +62,8 @@ public function needs($abstract)
      */
     public function give($implementation)
     {
-        if (is_array($this->concrete)) {
-            foreach ($this->concrete as $c) {
-                $this->container->addContextualBinding($c, $this->needs, $implementation);
-            }
-        } else {
-            $this->container->addContextualBinding(
-                $this->concrete, $this->needs, $implementation
-            );
+        foreach (Arr::wrap($this->concrete) as $concrete) {
+            $this->container->addContextualBinding($concrete, $this->needs, $implementation);
         }
     }
 }